ECAT Pre General Science Physics MCQ Test With Answer for Full Book

The commercial unit of electrical energy is :

• K Watt A
• KWH B
• Horse power C
• Joule D

The unit of decay constant is:

• Second A
• Metre B
• Hour C
• Year D
• Second^-1 E

the symbol to be used in relativity problems denotes:

• Dilated time A
• Proper time B
• Life time C
• Half time D
• None of these E

The conventional current is the name given to current due to flow of:

• Positrons A

• Positive charges

  B

• Negative charges

  C

• Both (A) and (C)

  D

• None of these

  E

There is present in paraffin a large amount of:

• Nitrogen A
• Hydrogen B
• Carbon C
• Baryllium D
• Lithium E

Electric intensity at a place due to a charged conductor is a

• Scalar quantity A
• Vector quantity B
• Semi vector and semi scalar C
• Dimensionless quantity D
• Both A and D are true E

In the formula B= µ̻ nl, the symbol n denotes:

• Total number of turns of solenoid

  A

• Number of turns per unit length

  B

• Number of turns per unit volume

  C

• Numbers of turns per unit area

  D

• Number of moles

  E

Which of the following does not obey ohm's law?

• Copper A
• Al B
• Diode C
• None D

For the working of a heat engine, there must be

• a source of heat at high temperature A
• a sink at low temperature B
• both of them C
• none of them D

The magnifier forms a virtual image of the object at:

• None of these A
• Both A and B are correct B
• Much farther than the least distance C
• Least distance of distinct vision D

For a n-p-n transistor, the conventional current equation can be written as

• I_E+ I_C= I_B A
• I_C- I_B= I_E B
• I_C+ I_B= I_E C
• I_B+ I_E= I_C D

The electric potential at the surface of an atomic nucleus (Z = 50) of radius 9.0 x 10^-15 is

• 9 x 10⁵V A
• 9 V B
• 8 x 10⁶V C
• 80 V D

After alpha decay the atomic number of the atom

• increase by four A
• decreases by two B
• increases by two C
• decrease by four D

The current that flows through the coil of a motor causes:

• Its shaft to revolve

  A

• Its brushes to rotate

  B

• Motor to move

  C

• Its shafts to rotate

  D

• None of these

  E

The lines of a difference grating have a spacing of 1.2 m. When a beam of monochromatic light is incident normally on the grating. The first order maximum monochromatic light is.

• 1200 nano meters A
• 450 meters B
• 600 nano meters C
• 700 nano meters D

A car moves for half of its time at 80 km/h and rest half of time at 40 km/h, The total distance covered is 60 km. What is the average speed of the car?

• 60 km/hr A
• 80 km/hr B
• 120 km/hr C
• 180 km/hr D

At the temperature, a body emits radiation which is principally

• of long wavelengths in the visible region A
• of long wavelengths in the invisible infrared region B
• of short wavelength in invisible ultraviolet region C
• none of these D

The isotope/s of hydrogen is /are:

• Protium A
• Deuterium B
• Tritium C
• Both (A) and (B) D
• All of these E

Which of the following material has smaller has life

• uranium A
• polonium B
• radium C
• radian D

In a semi-conductor material, current flows due to

• positive charge A
• negative charge B
• both of them C
• none of them D

• 5μF A
• 10μF B
• 3μF C
• 6μF D

In a transistor, the central region is called

• collector A
• emitter B
• base C
• none of them D

At constant temperature, on increasing the pressure of a gas by 5%, its volume. The final temperature of the gas will be

• 81 K A
• 355 K B
• 627 K C
• 627°C D

The property of light which does not change with the nature of the medium is

• Frequency A
• Amplitude B
• Wavelength C
• None of these D

Force is a:

• Scalar quantity A
• Base quantity B
• Derived quantity C
• None of these D

A flywheel accelerates from rest to an angular velocity of 7 rad/sec in 7 seconds. Its average acceleration will be:

• 49 rad/sec² A
• 1 rad/sec² B
• 0.16 rev/sec² C
• Both A and C D
• Both B and C E

One radian is:

• Greater than one degree A
• Less than one degree B
• Equal to one degree C
• None of them D

In a moving coil galvanometer, the deflecting couple depends upon

• area of the coil A
• number of turns of coil B
• value of magnetic field C
• all of the above D

F = I(L x B) is a

• vector A
• scalar B
• unit vector C
• none of these D

Electric field lines emerge from the charge in:

• One dimension

  A

• Two dimensions

  B

• Three dimensions

  C

• Four dimensions

  D

• None of them

  E